1. Field of the Invention
The present invention relates to a method of managing files of a portable information terminal, and more particularly, to a method of automatically upgrading a program installed in a portable information terminal to a most recent version. The present application is based upon Korean Application No. 97-13417, which is incorporated herein by reference.
2. Description of the Related Art
In general, a portable information terminal is a multimedia product having functions of a cellular phone, a wireless facsimile, a radio pager, and an electronic organizer. It is possible to send document information to a master server and retrieve document information from the master server regardless of the time or location using the portable information terminal. Also, it is possible to detect and receive information from a data base connected to a personal computer (PC).
FIG. 1 shows the structure of a general network comprised of servers and portable information terminals. Files commonly used by all portable terminals are stored in a common directory of a master server 110. Personal files of individual users (i.e., user 1, user 2, etc.) are stored in a private directory of the master server 110. Local servers 120 receive common files and personal files of users from the master server 110, store them in the directories of the respective users (user 1, user 2, etc.) and transfer relevant files when the portable information terminals 130 are connected to the local servers 120.
When files to be installed in a portable information terminal 130 are recorded in the private directory of the master server 110, the respective local servers 120 receive the files and transfer them to the user directories. When the portable information terminals 130 are connected to the local servers 120, the users receive the files from the directories. Here, the files are transferred in a directory unit since they are related to each other. That is, the transfer of the files is completed when all of the files in the directory are transferred. The files in the concerned directories of the local servers 120 are deleted after the files are transferred to the portable information terminal 130. Therefore, the portable information terminal 130 needs temporary memory for receiving files. However, the master server 110 cannot transfer additional or amended program files to the portable information terminal 130 if the size of the program files is larger than the memory available in the portable terminal 130.